Best Answer: I'd say about 10-15 mins walking at a relatively average pace!! Fastest time to run a mile is around 4 minutes. The average time to walk a mile is 12 minutes, so half a mile would be 6 minutes. i walk a mile every morning in 15-20 minutes, so probably 10 minutes. At a semi rapid rate about 7 1/2 minutes.
Too much dryness in nasal cavity results in burning inside the nose. Allergy to certain foods can also lead to burning and inflammation in nasal mucus membrane. Nose picking and digging can make the nasal lining dry, which in turn can cause burning sensation in the nose. Diseases such as multiple sclerosis, stroke can cause burning sensation in the nose.
Nasal sprays and other allergy medications are very safe medications that have very few side effects. I can think of no reason that using these medications over the summer (months ago now) would somehow have damaged the inside of your nose in any way and led to this problem you are having now with a strange burning smell inside of the nose.